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By Robert McIvor, Sami Makni, Andreia Rosa, Claude Gagnon

In response to the Natural Resources Canada “Crush It Challenge,” Corem partnered with the University of British Columbia and led a project to develop and demonstrate the use of high-pressure grinding to replace the workhorse of the industry, wet ball milling. Two plant case studies, a small tonnage gold recovery operation and a large tonnage copper recovery operation, were carried out. Plant circuit performances were compared to pilot plants operated on the same circuit feed setup to represent the novel equipment and flowsheet that was developed to produce separation circuit feed. Numerous obstacles to industrial implementation of high-pressure grinding in this role which were recognized at the outset of the work were successfully addressed. In both cases, comminution equipment energy savings alone and final stage total circuit energy savings exceeded 60% and 50%, respectively. Downstream mineral separation performance was the same or better.

Nov 28, 2023

By G. T. Lineberry

A systematic, comprehensive, balanced approach is presented for underground coal mine design, capable of being standardized and generalized. This approach epitomizes professionalism and must preceed the physical product. Design involves a varied senior staff and requires extensive selective input data. Engineering follows a total systems approach, operating in and for a constricting geologic setting, heavily constrained for safety, health, and environmental protection. It must also anticipate execution and operation. Engineering prominence and momentum are maintained, with sub-optimizations balanced by judgments--the "art and science" of engineering. The flow-chart starts with organized input data: Company Capabilities, Property Description, Geologic Analysis and Reserve Analysis. Engineering combines Ground Control with Excavating and Bulk Handling to map feasible Mining Methods, the crucial Milestone Diagram. Layout and Sequencing follow, with numerous alternatives examined. Scheduling is performed on the best designs, using predicted advance (performance) rates. Active and mined-out areas are isolated into time-related parcels, or increments, for the mine life. Bulk Handling, Life Support (especially ventilation and drainage), and Normal Support systems occupy each parcel. Regulations are then checked. Management concerns are covered, and an Economic Analysis is performed for profitability. This and the design represent an Initial Tentative Solution. Continued iterations produce multiple and improved choices.

Jan 1, 1987

By Wallace Macgregor

The direct investment role of Middle Eastern oil producing countries in future world-wide mineral development probably will be a limited one for the next five years. Their needs and their longer range economic objectives substantially preclude any such risk taking ventures. There is, of course, the possibility of political in- vestment. One hears many rumors and doomsday calculations of what the Arabs might do with the rising accumulation of surplus funds. Up to now, this kind of investment has been more in rhetoric than in money. For the most part, oil producing countries of the Middle East have been, and will be, investing surplus funds with strong emphasis on the preservation of capital. They will seek security first and yield second just like any other prudent investor. In several respects, this is regrettable. A direct infusion of risk capital into mineral development, especially in the Third World countries, is a constructive way of enhancing their earning power which many desperately need just to stave off starvation. It would also be a good way of eliminating material shortages in the industrialized world. Most important of all, it would help to ultimately reduce inflation without imposing the hardship of recession. So why isn't it done?

Jan 1, 1975

By Larissa Koroznikova, Steve Durkin, Patrick Bouwmeester, Michael Tuck

In currently used mining methods, blasting techniques often causes dilution of valuable ore and results in costly processing requirements. In the context of narrow vein mining of thin and highly concentrated orebodies there is a need of a mining method that can reduce dilution in order to remain economically viable. This research project explored the viability of a new mining technology, thermal fragmentation, in narrow vein mining. Thermal fragmentation technology uses a flame jet to produce extreme heat that spalls the surrounding rock to a strategically located drill hole, as an alternative to traditional blasting. This paper creates a net present value (NPV) model of a mining method using thermal fragmentation, as well as for an existing method used for narrow vein mining; comparisons and evaluations were made regarding the feasibility of the new technology. It was found that while overall costs for thermal fragmentation were relatively high, reductions in wages, haulage and processing costs, as well as increased productivity and ore recovery, meant that the new method would improve the financial performance of any operation. These results identify that there is an opportunity to introduce the thermal fragmentation technology to narrow vein mines within Australia, in order to lower costs and increase profit.

By Adam Bedell, Paul Derby, Brad Crenshaw

Modified contact grouting was introduced almost 15 years ago as a methodology combining traditional contact grouting and consolidation grouting to address groundwater infiltration into hard rock tunnels that utilize cast-in-place concrete as permanent tunnel support. This process has been used on additional tunnels (since initially presented) as a measure to mitigate both groundwater infiltration and exfiltration. During this time, self-sealing grouts have been developed and have been added to the process to further reduce groundwater infiltration that occurs through cracks and discontinuities within the concrete liner itself. This modification is presented and additional results from the grouting process are discussed.

Jun 13, 2021

By Ted H. Eyde

The Bowie chabazite deposit has yielded the most mined tonnage of any natural zeolite deposit in the United States. Since 1962 the deposit has yielded about 12,000 tons of crude chabazite, with an estimated market value of S30 million when sold as an activated molecular -sieve product. Between 1,000 and 1,500 tons of high-purity crude lump chabazite is now produced annually by stripping and selectively mining the lower, massive, half-foot-thick, "high-grade" bed. All of the chabazite is still shipped out of State for grinding prior to extrusion and activation. Zeolite minerals were discovered at the Bowie deposit in 1875, when Oscar Lowe identified a hydrous silicate related to chabazite or stilbite from a tuff bed that cropped out in the San Simon Valley. It was not until 1959, however, that chabzite, erionite, and clinoptilolite were positively identified as the principal constituents of an altered vitric-tuff horizon that crops out in the area originally described by Lowe. Shortly after the rediscovery of zeolite minerals in the San Simon Valley, several of the major producers of synthetic zeolites acquired land positions covering the outcrops, including projected extensions, and began exploration drilling. By 1980 all of the known chabazite reserves had been acquired by five companies and two individuals. The more than 3,000 holes drilled to explore the deposit and the excellent exposures provided by the strip-mined areas indicate that the chabazite-bearing horizon (known as the marker tuff) is confined to a flat-lying lacustrine section known to the operators as the Green Lake Beds. The deposition of the parent airborne vitric ash and subsequent zeolitic alteration was controlled by many factors, including the lake-bottom topography, depth and cation content of the saline-alkaline lake water, and proximity to post-depositional erosion surfaces. Zeolitic alteration was complete when an extensive system of younger paleochannels deeply eroded the Green Lake Beds. This left only a few erosional remnants of the marker tuff and the lower "high-grade-bed" that constitute the present deposit. Both the channel gravels and the Green Lake Beds are overlain by a section of halite-bearing brown mud-stones, known as the Brown Lake Beds. The bowie chabazite deposit can be used as a model to guide the exploration and development of other zeolite deposits that formed in saline-alkaline lacustrine environments.

Jan 1, 1987

By Kenneth L. Clifford

We have heard a lot during the recession about the mining industry now competing in a world market for sales of such commodities as copper, lead, zinc, molybdenum, iron ore, and phosphate. If the US mining industry is to survive, do we not have to reduce direct operating costs to a minimum? How significant is labor cost compared to consumables, electricity, fuel, maintenance, materials, and transportation? Ore grade is ultimately the dominant factor; but can we offset its dominance by improving productivity? Is the US mining industry perhaps only 25-30% as productive as it might be? What prevents the industry from being more productive? Can we retrofit older plants to be more productive or does it take a new plant with the largest equipment available for each unit operation? Present Productivity A copper industry study a few years ago covering 13 US copper concentrators ranging from about 10-45 kt/d (11,000-50,000 stpd) showed that productivity did not vary with capacity above 18 kt/d (20,000 stpd). Operating productivity varied significantly, however, from about 180-635 t/d (200-700 stpd) per operating hourly worker in most units, but one operation had 900 kt/d (1,000 stpd). Concentrators with more than 545 t/d (600 stpd) per hourly worker were in the 23 kt/d (25,000 stpd) or more category. Maintenance productivity covered about the same range, but most concentrators were in the 270¬635 t/d (300-700 stpd) per hourly maintenance worker. Again, one company stood well above others by exceeding 1 kt/d (1,100 stpd). Total hourly productivity ranged from 125-280 t/d (140-310 stpd) per hourly worker for most concentrators. The company with the most productive operation, however, was above 455 t/d (500 stpd). Salaried worker productivity for most operations was in the 725 t/d to 1.2 kt/d (800-1,300 stpd) per salaried worker range. The best operation was 2.2 kt/d (2,400 stpd). The end result is, of course, tons per day per total personnel. Most operations fell in the 110-220 t/d (120-240 stpd) range with the best operation at 400 t/d (440 stpd). This is the productivity definition that is most directly related to unit costs. Many of these operations have made some productivity progress

Jan 11, 1983

By Russ Darr

New methods and techniques in the field of hydrogeology are being developed constantly. One of these advances has been brought about through the use of inexpensive microcomputers. The formulas used in this paper and developed by Theis, Jacob, Glover, Keck, and Dupuit are not new. The methods by which these formulas can be solved are now available to all who wish to get faster, less expensive, and more reliable answers. These methods involve the solution of standard groundwater formulas using microcomputers. Examples and case histories of these methods are presented

Jan 1, 1980

By J. J. Gusek

The Riley Pass strip mine is an abandoned uranium-bearing lignite deposit in Harding County, South Dakota, covering about 150 acres of highwalls, pit floor and mine spoils exhibiting elevated levels of radioactivity. Six reclamation design alternatives were developed, ranging from doing nothing to reclaiming to approximate original con-tour. The alternatives were evaluated for expense, site stabilization, and mitigation of public safety hazards. A comparative economic evaluation on three of the alternatives was completed for the Forest Service in selecting an alternative and substantiating federal funding requests. This evaluation included economic impacts associated with physical and radiologic health hazards, affects on recreational users, socioeconomic impacts and environmental improvement.

Jan 1, 1995

By Charlotte Abena Benyarku, Albert Buabeng, Eric Stemn

The abstract highlights the increasing use of mobile equipment in mining and its contribution to accidents. The research analyzes injury narratives from Ghanaian surface gold mines to understand the involvement of mobile mining equipment in injuries and explore the use of injury narrative data as a human factors tool. The study identified priority human factor issues, such as operating mobile mining equipment, part removal/installation, and the operator's cabin. The use of Sankey diagrams for multivariable analysis effectively identified specific operator-centered issues that warrant further investigation for improved safety interventions.

Mar 29, 2022

By Dennis Asmussen

The peatlands of the U.S. and Canadian parts of the Upper Great Lakes region have a long history of modest utilization in agriculture, forestry, horticulture, and as natural undisturbed areas. Only recently have they been assessed as potential sources of non-renewable or renewable energy. This new interest in peatlands, should current proposals be realized, might mean the commitment of millions of acres to energy production purposes. The magnitude alone of this potential utilization of peatland signals the possibility of substantial environmental disturbance, local resource shortages, resource use conflicts, and social and economic change. Peat- land resource managers in the region are just beginning to weigh the advantages and disadvantages of large-scale peatland utilization. The Minnesota Department of Natural Resources has made a considerable effort to study peat resource management issues and will shortly make recommendations to the state legislature regarding utilization alternatives. What follows is a general discussion of peatland utilization and management trends in the region with a focus on Minnesota and its peatland management efforts.

Jan 1, 1980

By M. Mustafa Kahraman, Sean Dessureault, W. Pratt Rogers

Most contemporary mines have considerable amounts of data. Structured and unstructured large data sets are colloquially named big data. Much of the data in mining operations come from a variety of systems, each with different databases and reporting environments. Standard technology deployments create a Bsilo-ification^ of data leading to poor system benefit. Through modern server monitoring and systematic approach, data utilization and value can quantifiably be measured. The Data Utilization and Value Index (DUVI) can quantify business intelligence best practices and user interaction. This study seeks to provide a data management tool to measure data utilization across the process of converting data into action.

By J. Noll, C. DeGennaro, C. Zhou, J. Srednicki

"The personal dust monitor (PDM) (model PDM3700), as well as other electronic devices, can cause electromagnetic interference (EMI) which can disrupt the operation of some proximity detection systems (PDSs). A 15 cm (6 inch) minimum separation distance between the miner-wearable component (MWC) of the PDS and the electronic device usually avoids these disruptions, but due to the amount of equipment on a miner’s belt and the method of wearing the PDM in some situations, this distance can be difficult to always reliably maintain. Another method of reducing EMI effects is utilizing magnetic field shielding. The shielding capability of several different materials was investigated by surrounding the PDM with the material and quantifying the EMI. A copper mesh pouch reduced the EMI from a PDM3700, allowing a minimum separation distance of 10 cm (4 inches) instead of 15 cm (6 inches) as shown in a previous study for an unshielded PDM. A MU-metal box had a better shielding effectiveness, as it further reduced the minimum separation distance to less than 7 cm (2.8 inches). Shielding reduced the EMI of the PDM with MU-metal providing better results than the copper mesh. These materials may be beneficial for shielding individual components of the PDM or for constructing a shielded pouch. However, before the advantages of a shielded pouch can be determined, the effects of just the shielding material (metal) on the PDS needs to be quantified. INTRODUCTION According to statistics from the Mine Safety and Health Administration (MSHA), 43 miners have been fatally struck or pinned by a continuous mining machine (CMM) since 1984. In an effort to prevent future striking and pinning fatalities from occurring, proximity detection systems (PDSs) have been developed and are required on all operating CMMs in underground coal mines, with the exception of full-face CMMs, by 2018 (MSHA, 2015)."

Jan 1, 2018

By Paul D. Tomlingson

An effective maintenance program ensures the adequate availability of production equipment. In turn, this availability enables production to maximize utilization and successfully meet production targets. An overall production strategy is necessary to draw all departments toward this common effort. Only then will production targets be met. From the maintenance view this means that production must comply with PM and repair schedules. Purchasing must supply parts and materials on time. Mine engineering must not overwhelm maintenance with non-vital construction. Accounting must provide correct, timely cost information - - etc. This strategy - - its content, effectiveness and enforcement is the responsibility of the mine manager . . . his alone. This paper describes a successful approach to maintenance within this strategy.

Jan 1, 1979

By Murat Erdemoğlu, Turan Uysal, Thierno Saidou Barry, Mustafa Birinci

The rapid development of the global alumina and aluminum industry is straight coupled with the demands and the needs of these materials. Nowadays, the only well-known accessible resources to produce alumina and aluminum are bauxite ores. But bauxite ores are limited, and the remaining exploitable reserves do not have high contents in alumina. In countries where there is little or no bauxite reserves or where the recovery of existing bauxite ores to produce alumina with the Bayer process are not economic, alternative resources for alumina have been explored. The most attractive resources for replacing bauxites are aluminosilicate clay minerals and coal fly ash. The important processes developed for the recovery of alumina from these sources are acid leaching and alkaline leaching processes. The acid leaching is known as the most efficient in which thermal and mechanical activation are included for improving the performance of the process. The objective of this review is to give a comprehensive insight on the production of the alumina from thermally or mechanically activated clays and coal fly ash by hydrochloric, sulfuric, and nitric acid leaching processes.

By Frank J. Foster

This Paper will deal with Bucketwheel Suction Dredging and its particular relationship to mining applications. There will be comparisons with other methods of suction dredging and descriptions of two recent bucketwheel installations in the mining area. The Directory of World Dredging Fleets published in the `larch 1984 edition of World Dredging magazine shows that there are about 1.000 conventional Cutterhead Dredges listed throughout the world with 289 in the United States. There are 242 Bucketline Dredges listed throughout the world of which only 6 are in the United States. These figures are not completely accurate because several units are known to the author that are not on the list and, of course, there may be others.

Jan 1, 1984

By R. M. Tyson

Sulfides present in the troctolitic and footwall rocks are placed into one of three major zones (hornfels, cloud, and basal) on the basis of their stratigraphic position and mineralogy. Hornfels sulfides, enriched in Fe, represent remobilized sedimentary sulfide. Sulfides from the Cloud Zone are probably magmatic and are enriched in PGE, Cu, Ni, and Ag. The basal sulfides, composing most of the ore, resulted from contamination of the magma by remobilized sedimentary sulfide. The basal sulfides exhibit a differentiation trend in their mineralogy and chemistry. PGE, Cu, and Ag are enriched with increasing differentiation which is attributed to fractionation within an immiscible sulfide liquid.

Jan 1, 1986

By R. E. Murray

"It is a gloomy moment in the history of our country. Not in the lifetime of most men has there been so much grave and deep apprehension; never has the future seemed so incalculable as at this time. The domestic economic situation is in chaos. Our dollar is weak throughout the world. Prices are so high as to be utterly impossible. The political cauldron seethes and bubbles with uncertainty. Russia hangs, as usual, like a cloud, dark and silent, upon the horizon. It is a solemn moment. Of our troubles, no man can see the end." By now you, no doubt, are asking, 'Where did Murray get this bit of philosophy?' Well, I obtained it from an editorial entitled. "The Worst of Times", which was published in the Harper's Magazine in 1847. That's right, 1847! The parallelism between the situation in our country at this time and in 1847 is un- canny. But wait, there is one major exception the size of government. To my knowledge, the citizens of 1847 were not stifled by the extreme governmental excesses that we are experiencing today.

Jan 1, 1980

By James R. Aggson

This paper summarizes the research effort that was conducted as part of a cooperative agreement between the U.S. Bureau of Mines, Denver Mining Research Center and the Pittston Company. The objective of this investigation was to further the understanding of the floor heave ground control problems that have plagued underground mining of the Beckley coalbed in southern West Virginia. Floor heave is both economically and structurally undesirable. Floor heave is accompanied by a redistribution of stresses and loads that are associated with an underground opening. This redistribution of stresses may cause roof or pillar problems that otherwise would not have occurred. The floor heave that occurs in the Beckley coalbed is not cons1dered to be caused by "squeezing" or plastic flow of the materials involved. The "squeezing" type floor heave is normally associated with relatively weak floor members that contain significant amounts of clay mineralization. The floor members in the Beckley coalbed are competent, relatively strong materials which fail in a manner that can best be described by the term "buckling." This buckling-type failure is indirectly related to the time-dependent deformation properties of the materials involved, but is considered to be more of a slender column, or panel, type failure than a "squeeze" or "flow"-related failure. The Beckley coalbed has had a history of floor heave ground control problems. The Glen Rogers mine, which opened in the 1920's, experienced extensive floor heave. In a report dated April 1929, James P. Keatley of the West Virginia State Department of Mines described the floor heave in the Glen Rogers mine. Several observations listed in the Glen Rogers report that appear to be consistent with current observations follow: 1. Water plays no apparent part in the floor heave process. 2. No evidence of gas has been found in the floor. 3. The thickness of the overburden, which varies from 183 to 396 m (600 to 1300 ft), has no relationship to the floor heave. In the conclusions of the 1929 report on the Glen Rogers mine, Keatley states, "A statement in brief as to the cause (of floor heave) would lie that an undetermined natural condition doubtless augmented by former and present mining methods causes the bottom to heave." As this report will show, Mr. Keatley's insight into the problem was most accurate. The "undetermined natural condition" is the existence of a biaxial, horizontal, compressive stress field. This stress field is in excess of that which would be expected from gravity loading. This stress field and the material properties of the floor rock combine to cause the floor heave that has been experienced. The floor heave that occurs in the Beckley seam generally occurs as arching, with a tension fracture, near the center of the floor span or as a break near the rib followed by vertical deflection (of the floor) at the rib and sloping of the floor across the entry. Examples of the floor heave are shown in Figures 1 and 2. The two types of floor heave are merely different manifestations of the same basic failure mechanism. When the entries experiencing floor heave were identified on a map of the mine under investigation, it was apparent that there was a relationship between the floor heave and the direction of the entries. The main entries, which are used for ventilation and haulage, experienced the majority of the floor heave. This directional relationship suggested a directionally related loading mechanism, or more specifically, a biaxial, horizontal stress field that exceeds what would be expected by gravity loading. Since the main entries were oriented at a bearing of N25oW, it was hypothesized that the maximum compressive component of the horizontal stress field was at 90° to these entries or at a bearing of N65oE. An in Situ testing program was developed to test this hypothesis and investigate the floor heave problem.

Jan 1, 1978

By C. D. Keith

Erie Mining Company, a pioneer in the iron ore pelletizing industry, has continued to develop methods and equipment to improve cost and quality. Under the management of Pickands Mather & Co., this property, owned by Bethlehem Steel Corporation, Youngstown Sheet and Tube Company, Steel Company of Canada, Ltd., and Interlake, Inc., has initiated a number of operating improvements for the taconite industry. One of the most noteworthy of these, which is applicable to the entire mineral industry, is the principle of fine screening with rappers (FSR). Erie's original efforts in the field of fine screening, which date back to 1961, were described in the April 1967 issue of the MINING ENGINEERING magazine. In that same month, Erie placed into operation a full scale PSR and regrind plant addition, capable of processing 10.3 million long tons of iron ore concentrates, produced by conventional taconite grinding, classification, and magnetic separation methods. Since this first successful commercial operation of the PSR principle et Erie, it has been applied in eight other iron ore beneficiation plants end is being tested by other U.S. and foreign companies. In addition to the use of PSR units at Erie Mining Company, Pickands Mather has applied PSR to other of its managed properties end to projects under development. This paper covers these applications as well as a now application at Erie Mining Company.

Jan 1, 1971